Units/Equations
What are the units for Force?
Newtons
Which value is always higher? Static friction or kinetic friction?
Static
A box on a table has a weight of 10N. What is the normal force of the table?
10N
A soccer ball lies motionless on a field. It only starts rolling when a player kicks it.
Which of Newton's 3 laws best describes this scenario?
1st
What does the greek letter mu represent?
Coefficient of Friction
If we want to decrease the fricition of a surface, what must we do to the coefficient of friction of that surface? Increase or decrease?
decrease
A ball has an acceleration of 5m/s^2. If it has a mass of 10kg, what was the force applied?
F = 50N
3rd law
F=ma
A book slides across a table to the right. Which direction does the force of friction act?
Left
A force of 5N is applied to a mass of 5kg, what is the acceleration of the mass?
a = 1m/s^2
3rd
What is the equation for weight?
W=mg
A box is sitting on a table. What force is equal and opposite to the weight of the box?
Normal force.
What is the weight of a box that has a mass of 10kg?
W = 98N
When you jump off a small boat into water, the boat moves backward.
3rd
What is the equation for Friction force?
f(friction) = (mu)*Normal force
What happens to the force of friction if the weight of an object doubles?
Force of friction also doubles.
Daily Double
A man has a wieght of 400N. His coefficient of friction between his shoes and the road is 0.5. What is the frictional force?
It is easier to push a shopping cart that is empty compared to a full shopping cart.
2nd law.
The same force causes less acceleration with more mass.